An auto-scaling technology exists in which, in an operational model for distributing a load by using a load balancer (LB), when a load on each operational server increases, an operational server that is an operation distribution destination is automatically added.
In addition, an automatic failover technology exists in which, in an operational model for distributing a load by using a load balancer, when an operational server goes down, the operational server that has gone down is restarted in another VM host.
Further, a processing distribution system exists in which the above respective technologies are combined. In this case, auto-scaling and automatic failover may be simultaneously performed (for example, Japanese Laid-open Patent Publication No. 2016-58005).
Note that related technologies are described, for example, in Japanese Laid-open Patent Publication No. 2015-194958, Japanese Laid-open Patent Publication No. 2012-198843, Japanese Laid-open Patent Publication No. 2016-058005 and International Publication Pamphlet No. WO2016/075771.
In the case of an operational model to which the respective technologies are simultaneously applied, an operational server fails to recognize the state of another operational server, and therefore the operational server fails to determine whether an increase in a load results from an increase in the volume of operations or the failure of another operational server. The operational server issues an overload report when a load increases, and therefore the operational server only activates auto-scaling.
In contrast, a management server can recognize the failure of an operational server, and therefore the management server can activate automatic failover. However, the management server is not directly involved in the operation of the operational server, and therefore the management server fails to recognize that the operational server has activated auto-scaling.